<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>1</title>
</head>
<style>

</style>
<body>

<script>
for (let i = 0; i < 5; i++) {
  (function f(i) {
    setTimeout(() => {
      console.log('i:',i)
    },1000)
  })(i)

}

let url = 'http://xxx.com?a=1&b=2'
function query2json(url){
  let  result = url.split('?')[1]
  let arr = result.split('&')
  let obj = {}
  arr.forEach(item => {
    let  arr2 = item.split('=')
    obj[arr2[0]] = arr2[1]
  })
  return obj
}

console.log(query2json(url))

class Vue{

}
let obj = new Vue()
console.log('obj:',obj)
console.log('obj.constructor:',obj.constructor)
console.log('obj.__proto__.constructor:',obj.__proto__.constructor)
</script>
</body>
</html>
